1. Field of the Invention
The present invention is generally related to a drain system for a marine propulsion engine and, more particularly, to a drain system that utilizes pressure actuated valves to open one or more drain passages to allow water to drain from the engine block and various other components of the marine propulsion system.
2. Description of the Art
Marine propulsion systems used for pleasure craft or working boats of various sizes typically use water from the body of water in which they are operated for engine cooling functions. This water is used in the cooling systems of the marine propulsion devices. Whether the marine propulsion cooling system is an open system, in which sea or lake water is passed through the engine to directly remove heat from the engine, or a closed system in which lake or sea water is drawn into a heat exchanger to remove heat from a coolant that is enclosed within a recirculated system to remove heat from the engine, lake or sea water is continually conducted through various conduits of the cooling system. It is therefore important to be able to remove the lake or sea water from the many passages and conduits of the marine propulsion system in order to avoid trapped water that could freeze and cause serious damage to the propulsion system.
It is common to provide a marine propulsion system with numerous openings through which cooling water can be drained, either into the bilge of the boat or overboard. Many different techniques and processes have been developed in order to facilitate the draining of the cooling system of a marine propulsion device by the operator.
U.S. Pat. No. 5,362,266, which issued to Brogdon on Nov. 8, 1994, describes a fresh water flushing system for a marine engine in a boat for use, whether the boat is in or out of the water. The system comprises a control panel mounted on the interior of the boat, a plurality of tubular xe2x80x9cTxe2x80x9d shaped interconnection fittings in a raw sea water cooling conduit, and a fresh water flush valve therebetween. The components are connected for fresh water fluid flow with a plurality of standard radiator hoses. The fresh water flush valve has a valve plunger for establishing fresh water flow between the control panel and the xe2x80x9cTxe2x80x9d shaped interconnection fittings. Further, the fresh water flush valve has a plurality of axial outlet ports to proportionally direct the flow of fresh water to the appropriate xe2x80x9cTxe2x80x9d shaped interconnection fitting in the raw sea water cooling conduit of the marine engine. A valve plug is provided to secure a positive closure when the fresh water flow is disconnected. The valve plug has a tapered body and an xe2x80x9cOxe2x80x9d ring to effect a positive seal and ensure that no fluid backflow occurs when the flushing system is not in use and operation of the marine engine is operating under normal conditions in sea water. All of the fixed and moveable parts are fabricating from material that resists salt air and salt water corrosion.
U.S. Pat. No. 4,533,331, which issued to Bland on Aug. 6, 1985, described a vent and drain assembly for marine propulsion devices. An outboard motor includes a powerhead shroud defining an engine compartment for an internal combustion engine and a vent and drain assembly for ventilating the engine compartment to the atmosphere and for draining liquids, such as water, from the engine compartment. The vent and drain assembly includes a valve member movably disposed in an aperture at a low point in the bottom wall of the powerhead shroud opening the engine compartment to the atmosphere. The valve member includes a domed portion which extends through the aperture and defines a cavity for entrapped air and an annular sealing flange which is located exteriorly of the shroud bottom wall. The valve member is held by gravity in an open position wherein the sealing flange is displaced outwardly from the shroud bottom wall for ventilation and draining and is moved to a closed position wherein the sealing flange is in sealing engagement with the shroud bottom wall in response to a rise in the water level above the shroud bottom wall.
U.S. Pat. No. 6,050,867, which issued to Shields et al on Apr. 18, 2000, discloses a drain system for a marine vessel. The drain system is provided for a marine vessel in which three types of drain operations can be performed at one common location near the transom of the marine vessel. A multiple conduit structure is provided with a plurality of fluid passages extending at least partially through its structure. A first fluid passage allows the bilge of the boat to be drained. A second fluid passage allows multiple locations on the engine to be drained through a common port. A second sealing plug is provided to close the second passageway that prevents fluid communication between the various fluid conduits used to drain the cooling water of the engine. A third fluid passage is provided through the multiple conduit structure to allow lubricating oil to be drained from the engine. A single hole through the transom of the boat is all that is required to allow the multiple conduit structure to be attached to the boat and extend through the transom for the purpose of draining the bilge, the engine cooling water, and the engine lubricating fluid.
U.S. Pat. No. 5,628,285, which issued to Logan et al on May 13, 1997, discloses a drain valve for a marine engine. The drain valve assembly for automatically draining water from a cooling system of a inboard marine engine when the ambient temperature drops to a preselected value is described. The drain valve includes a cup-shaped base having a group of inlets connected to portions of a cooling system of the engine to be drained, and an open end of the base is enclosed by a cover. Each inlet defines a valve seat and a sealing piston is mounted for movement in the base and includes a series of valve members that are adapted to engage the valve seats. An outlet is provided in the side wall of the cup-shaped base. The valve members on the sealing pistons are biased to a closed position by a coil spring and a temperature responsive element interconnects the sealing piston with the cover. The temperature responsive element is characterized by the ability to exert a force in excess of the spring force of the coil spring when the ambient temperature is above approximately 50 degrees F., to thereby maintain the valve members in the closed position. When the temperature falls below the selected temperature, the temperature responsive element will react, thereby permitting the valve members to be opened under the influence of the spring to automatically drain water from the cooling system of the engine.
U.S. Pat. No. 4,875,884, which issued to Meisenburg on Oct. 24, 1989, discloses a marine propulsion device with a thru-transom engine oil drain system. A fluid flow tube is provided which extends from the lower portion of the engine oil pan to a point on the boat transom below the pan. The upper end portion of the tube is connected through a control valve which communicates with the pan interior. The lower or discharge tube end portion is connected through a fitting extending through the transom. A removal plug is associated with the fitting and, when removed, permits oil to drain out through the transom and into an oil receptacle when the control valve is open.
U.S. Pat. No. 4,741,715, which issued Hedge on May 3, 1988, discloses a pressure actuated drain valve for marine drives. The pressure actuated drain valve for automatically draining the cooling water from a marine drive engine when the engine is stopped is disclosed. The drain valve includes a spring-loaded diaphragm which moves to a closed position when the engine water pump is operating to close an outlet from the engine cavities to be drained. The diaphragm automatically moves to its open position when the engine water pump is off to open the outlet to allow cooling water to drain from the engine cavities.
U.S. Pat. No. 4,699,598, which issued to Bland et al on Oct. 13, 1987, describes a marine propulsion device water supply system. The propulsion device comprises an internal combustion engine, a propulsion unit adapted to be pivotally mounted on the transom of a boat for pivotal movement relative to the transom about a generally vertical steering axis, and about a generally horizontal tilt axis, the propulsion unit including a propeller operably connected to the engine, a pump for pumping water from the exterior of the propulsion unit to the engine, and a conduit extending from the pump to the engine and having a low point below both the pump and the connection of the conduit to engine, and a drain for draining water from adjacent the low point of the conduit.
U.S. Pat. No. 5,980,342, which issued to Logan et al on Nov. 9, 1999, discloses a flushing system for a marine propulsion engine. The system provides a pair of check valves that are used in combination with each other. One of the check valves is attached to a hose located between the circulating pump and the thermostat housing of the engine. The other check valve is attached to a hose through which fresh water is provided. Both check valves prevent water from flowing through them unless they are associated together in locking attachment. The check valve attached to the circulating pump hose of the engine directs a stream of water from the hose toward the circulating pump so that the water can then flow through the circulating pump, the engine block, the heads, the intake manifold, and the exhaust system of the engine to remove sea water residue from the internal passages of the surfaces of the engine. It is not required that the engine be operated during the flushing operation.
U.S. Pat. No. 6,135,064, which issued to Logan et al on Oct. 20, 2000, discloses a marine drain system. An engine cooling system is provided with a manifold that is located below the lowest point of the cooling system of the engine. The manifold is connected to the cooling system of the engine, a water pump, a circulation pump, the exhaust manifold of the engine, and a drain conduit through which all of the water can be drained from the engine.
U.S. Pat. No. 6,089,934 which issued to Biggs et al on Jul. 18, 2000, discloses an engine cooling system with a simplified drain and a flushing procedure. An engine cooling system is provided with one or more flexible conduits attached to drain openings of the engine and its related components. First ends of the conduits are attached to the drain openings while the second ends are sealed by studs attached to a plate of a stationary bracket. A retainer is slidably associated with the flexible conduits and attached to a tether which is, in turn, attached to a handle. By manipulating the handle, the tether forces the retainer to slide along the flexible conduits and control the position of second ends of the flexible conduits. This allows the system to be moved from a first position with the second ends of the conduits above the first ends of the conduits to a second position with the second ends of the conduits below the first ends and in the bilge of the boat. The system allows an operator to stand in a single location and move the drain system from the first and second position and back again without having to reach down into the engine compartment to remain drain plugs. The system allows the cooling system to be easily drained or flushed.
When a boat operator intends to drain the water from the cooling system of a marine propulsion device, the various drain conduits must be opened to allow the water to flow out of the engine cooling system and into either the bilge of the boat or overboard. Although many different devices have been developed to facilitate this procedure, some means must be provided to actually open the conduits. This could be the manual procedure of unthreading plastic plugs from drain openings on the engine, activating electrical switches which, in turn, cause remote valves to open to allow water to drain from the engine, or manually manipulating hoses to accomplish this process.
It would therefore be significantly beneficial if a means could be provided whereby a boat operator could easily and simply command the opening of all drain conduits, from a single remote position conveniently accessible to the boat operator, in order to cause the draining of the engine cooling system to occur. It would be further beneficial if this procedure could be accommodated without the need for electrical wires extending between the boat operator""s position and the position of the various drain valves located around the engine. It would also be significantly beneficial if this procedure could be accomplished without the need of electrical or mechanical power provided by other than manual means.
A drain system for a marine propulsion apparatus made in accordance with the preferred embodiment of the present invention comprises a cooling water conduit system which is connectable in fluid communication with an engine of the marine propulsion apparatus. The cooling water conduit system can be, in its simplest embodiment, a simple drain hose connected to a drain location on the engine or its associated cooling system. The present invention further comprises a first pressure actuated valve disposed in fluid communication with the cooling water conduit system. In its simplest form, the pressure actuated valve is a pneumatic valve connected in fluid communication with the cooling water conduit system and having a closed status and an open status. In the closed status, flow through the drain hose for the cooling water conduit system is blocked while in the open status, this flow is permitted. The present invention further comprises a pressure controller connected in fluid communication with the first pressure actuated valve. In its simplest form, the controller comprises a manifold housing that distributes pressure from a central location to one or more pressure actuated valves connected to it. The pressure controller housing provides a means to connect incoming fluid flow that provides a pressurized fluid to the pressure actuated valve to change its status. In certain embodiments of the present invention, the controller also provides indicators, or visual annunciators, that indicate that the valve has moved to an open drain position. The indicators will only extend from their housings when the valve has completely opened. When this occurs, supply pressure is allowed to enter the indicator lines. Although these indicators are technically pressure indicators, the pneumatic connections result in their being indicators that the drain valve has opened as intended and that draining of the engine cooling system is occurring. The present invention further comprises a first pressure conduit connected in fluid communication between the first pressure actuated valve and the controller. The first pressure conduit transmits the pressure from the controller to the pressure actuated valve and allows the status of the pressure actuated valve to be changed from open status to closed status or from closed status to open status. In order to accomplish these actions, the controller can also be provided with a pressure relief valve that is manually operated.
The drain system of the present invention can further comprise an engine having an internal cooling system within the block of the engine wherein the cooling water conduit system is connected in fluid communication with the internal cooling system. This connection is typically accomplished by connecting one end of the cooling water conduit system to a drain opening in either the engine block, a component of the water cooled exhaust system, or any other drain location.
The present invention can further comprise a source of pressure connected in fluid communication with the controller. The source of pressure can be a motor driven compressor or, preferably, a hand pump that allows the boat operator to manually increase the pressure within the manifold of the controller and within the first pressure conduit in order to change the status of the first pressure actuated valve and, as a result, allow the cooling water to drain from the engine and its associated components. It should be understood that the first pressure actuated valve can be a pneumatically controlled valve or, in alternative embodiments, can be a hydraulically controlled valve.
In certain embodiments of the present invention, a second pressure actuated valve can be connected to the controller by a second pressure conduit, wherein both the first and second pressure conduits are connected in fluid communication with the manifold of the controller.
A pressure relief mechanism can be connected in fluid communication with the controller and can be manually actuated to relieve pressure within the controller and within the first and second pressure conduits to deactivate the first and second pressure actuated valves.
In certain embodiments of the present invention, one of the pressure actuated valves can be attached to a cooling water manifold which has internal passages and which is connected in fluid communication with the internal cooling system within the block of the engine. The cooling water manifold is disposed below the level of the lowest portion of the internal cooling system which normally retains cooling water when the engine is not operating. The first pressure actuated valve is connected to a drain opening of the cooling water manifold. A cooling water manifold of this type is disclosed in detail in U.S. Pat. No. (M09334), which is described above.
By providing pressure actuated drain valves, the present invention allows a boat operator to remotely actuate these drain valves by providing pressure at a centralized location at the controller. This arrangement avoids the need for complex mechanical devices to accomplish the draining procedure and also avoids the need for electrical wires extending from the boat operator""s position at the controller and extending to the various drain valves. Instead, the present invention allows the boat operator to pneumatically actuate the pressure actuated valves and to accomplish the draining procedure in a convenient and safe manner.